# 1991 Estoril Open – Singles

Sergi Bruguera won in the final 7–6$^{(9–7)}$, 6–1, defeating Karel Nováček.

## Seeds

* Andrés Gómez (first round)
* Emilio Sánchez (first round)
* Andrei Chesnokov (semifinals)
* Andrei Cherkasov (first round)
* Marc Rosset (first round)
* Juan Aguilera (first round)
* Karel Nováček (finals)
* Sergi Bruguera (champion)

## Draw
### Key

* Q = Qualifier
* WC = Wild card
* LL = Lucky loser
* Alt = Alternate
* SE = Special exempt
* PR = Protected ranking
* ITF = ITF entry
* JE = Junior exempt
* w/o = Walkover
* r = Retired
* d = Defaulted
* SR = Special ranking

### Finals

| Semifinals | Semifinals | Semifinals | Semifinals | Semifinals | Final | Final | Final | Final |
| 7 | Karel Nováček | 7 | 6 | | | | | |
| | Marián Vajda | 5 | 2 | | | | | |
| | Marián Vajda | 5 | 2 | | 7 | Karel Nováček | 6$^7$ | 1 |
| | | | | | 8 | Sergi Bruguera | 7$^9$ | 6 |
| 3 | Andrei Chesnokov | 4 | 6 | 3 | 8 | Sergi Bruguera | 7$^9$ | 6 |
| 8 | Sergi Bruguera | 6 | 2 | 6 | | | | |

### Top half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 1 | A Gómez | 4 | 3 | | | | | | | | | | | | | | | |
| | R Agénor | 6 | 6 | | | R Agénor | 2$^r$ | | | | | | | | | | | |
| Q | C Allgårdh | 6 | 5 | 2 | | J Sánchez | 5 | | | | | | | | | | | |
| | J Sánchez | 4 | 7 | 6 | | | | | | | J Sánchez | 5 | 3 | | | | | |
| | G Prpić | 6 | 6 | | | | | | | 7 | K Nováček | 7 | 6 | | | | | |
| | A Rahunen | 1 | 3 | | | G Prpić | 2 | 5 | | | | | | | | | | |
| | O Camporese | 1 | 3 | | 7 | K Nováček | 6 | 7 | | | | | | | | | | |
| 7 | K Nováček | 6 | 6 | | | | | | | | | | | | 7 | K Nováček | 7 | 6 |
| 4 | A Cherkasov | 2 | 6 | 5 | | | | | | | | | | | | M Vajda | 5 | 2 |
| | F Clavet | 6 | 4 | 7 | | F Clavet | 6 | 7$^7$ | | | | | | | | | | |
| Q | C Motta | 5 | 3 | | | T Carbonell | 2 | 6$^5$ | | | | | | | | | | |
| | T Carbonell | 7 | 6 | | | | | | | 3 | F Clavet | 2 | 6 | 3 | | | | |
| | N Marques | 6 | 3 | 6 | | | | | | | M Vajda | 6 | 0 | 6 | | | | |
| WC | E Couto | 2 | 6 | 1 | | N Marques | 6 | 5 | 3 | | | | | | | | | |
| | M Vajda | 7 | 3 | 6 | | M Vajda | 4 | 7 | 6 | | | | | | | | | |
| 6 | J Aguilera | 5 | 6 | 2 | | | | | | | | | | | | | | |

### Bottom half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 5 | M Rosset | 1 | 6 | 3 | | | | | | | | | | | | | | |
| | H Skoff | 6 | 1 | 6 | | H Skoff | 6 | 6 | | | | | | | | | | |
| | J Cunha Silva | 4 | 6 | 1$^r$ | | R Fromberg | 4 | 2 | | | | | | | | | | |
| | R Fromberg | 6 | 4 | 2 | | | | | | | H Skoff | 3 | 1 | | | | | |
| | J Arrese | 3 | 4 | | | | | | | 3 | A Chesnokov | 6 | 6 | | | | | |
| Q | C Mezzadri | 6 | 6 | | | C Mezzadri | 7 | 5 | 1 | | | | | | | | | |
| | H de la Peña | 4 | 2 | | 3 | A Chesnokov | 5 | 7 | 6 | | | | | | | | | |
| 3 | A Chesnokov | 6 | 6 | | | | | | | | | | | 3 | A Chesnokov | 4 | 6 | 3 |
| 8 | S Bruguera | 6 | 6 | | | | | | | | | | | 8 | S Bruguera | 6 | 2 | 6 |
| | M Koevermans | 3 | 3 | | 8 | S Bruguera | 6 | 6$^8$ | 6 | | | | | | | | | |
| Q | E Bengoechea | 7 | 4 | 6 | Q | E Bengoechea | 3 | 7$^{10}$ | 3 | | | | | | | | | |
| | V Paloheimo | 5 | 6 | 2 | | | | | | 8 | S Bruguera | 6 | 6 | | | | | |
| | R Furlan | 2 | 7$^7$ | 6 | | | | | | | R Furlan | 1 | 3 | | | | | |
| | T Champion | 6 | 6$^2$ | 1 | | R Furlan | 7 | 6 | | | | | | | | | | |
| | P Haarhuis | 6 | 6 | | | P Haarhuis | 5 | 3 | | | | | | | | | | |
| 2 | E Sánchez | 0 | 2 | | | | | | | | | | | | | | | |